Radio receiving apparatus



l March 4, 1930. S, WEBSBERG 749,364

RADIO RECEIVING APPARATUS Filed March 29, 1928 NVE TOR Patented Mar. 4A, 1930 UNITED STATES PATiazNTA OFFICE SIDNEY wmsnnno, OF BROOKLYN, NEW YORK, AssIGNoB OF ONE-HALF rro MonnIs .PIcnsON, OF BROOKLYN, NEW'YORK RADIO RECEIVING APPARATUS Application led March 29, 1988. Serial No. 265,529.

My invention relates to radio receiving apparatus.

The principal Object of my inventlon 1s to rovide a device that can be readily connected 5 1n the circuit of a house current, and which embodies means for preventing the tube or tubes used in the receiving set from being injured or burned out due to a rise in voltage in the power line, or due to any cause by rea- 1o son of which the voltage is raised beyond the normal.

A further object is to make the device of parts that are interchangeable as far as possible to reduce the cost of dies and the cost of assembling, the device being so constructed as to be assembled without the use of tools, and all the parts being held together by the screws or bolts which hold the casing portions together in co-operative relation.

Referring to the drawings which form a part of this specification,

Fig. 1 is a longitudinal view of the two half portions which comprise the casing, the upper view disclosing the electrical conducting elements assembled therein.

Fig. 2 is a cross sectional view of the device taken on line 2--2 of Figure 1, as it would appear when the casing portions are assembled.

The casing comprises two duplicate semi= cylindrical portions A, and A respectively,

made of suitable insulating mouldable material, and are held together by. the nut and bolt elements B, and B respectively, as shown in dotted lines in Figure 2, the portions each having a. recess C, as illustrated in dotted lines in Figure 2, to permit the nut and head of the bolt to rest within the circle or outer circumference of the cylinder.

Two slots D-D respectively extend the entire length of the casing portions, the depth of the slots corresponding to one half the width of the conductor elements E, and F, which rest therein as shown, so that they may be clamped firmly between the casing portions by the bolts B.

rlhe device is illustrated by full size drawings with the exception of the resistance and fuse wires, which are further described hereinafter. The elements E, are duplicates, and

the elements E are duplicates, and the elements F, are duplicates, one pair of each being used in each device as shown. Each of said conducting elements is bent or off-set at One end to provide an anchorage at each point G, 1n the casing, the slots being formed to correspond to provide abutments to prevent longitudlnal movement of said conductors in either direction.

A fuse wire H, rests in the slot between the adjacent ends of the conductors E and E in contact therewith. This fuse wire is very small in cross section and of such resistance as to melt before the resistance wire I, will burn out.

A recess J, is formed in the casing portions to receive the fused metal when the fuse melts, and is large enough to insure the complete breaking of the circuit.

A central recess K, is formed in the casing to provide a separate closed chamber to hold the resistance wire l, which is preferably formed in a helical coil, the ends of which overlie and contact with the adjacent ends of the conductors E, and E on the side opposite to that in which the fuse wire is located, to complete the circuit at this point.

The resistance wire is made of very ne wire, having a resistance equal to or slightly greater than that of the tubes of the set it is to be put in circuit with, or is designed to protect, and therefore the fuse wire and resistance wire are made in complimentary pairs, eachpair being designed for a set of tubes having a resistance less than that of the fuse and resistance wire, as will be readily understood.

The elements E and E are stiff, having very little resiliency, and therefore the conductors F, are made of thin resilient sheet' material. rlhe elements E and F, are held firmly in contact with each other in the In use the device is connected in the feed line between the source of power and the set to be operated. The resistance to the current increases as the voltage increases due to the increased heating of the wire, thus keeping the How of current thru the tubes fairly constant until the fuse wire or the resistance burns out as the voltage reaches the danger point.

The average six tube' set operates under a resistance of about 7 ohms with 110 volts. In such a set if the voltage is increased to say, 130 volts, the fuse would blow before the resistance would burn out, but if a bridge piece was used on one side of the circuit instead of the fuse, the resistance wire would burn out and disrupt the circuit, thus saving the tubes of the set from damage.

It has been found that the use of this device also prevents the whistling and noisy tones usually generated when .the voltages rises too high, the resistance serving to prevent the tubes from oscillating, and this feature of my invention is deemed of importance.

The device is so simple and the construction is so clearly shown in the drawings, that further description is deemed unnecessary.

"Having thus described my invention I claim as new:

1. A device for protecting the tubes of a radio receiving set, comprising a casing of insulating material, electrical conductors in said casing comprising two separated sections located in alignment with each other, a wire connecting said sections having a resistance greater than that of the tubes of the set to be protected, two other sectional conductors located in ali nment with each other, a fuse wire of preetermined resistance connectin said last mentioned conductors and'designe to fuse prior to the fusing temperature of said first wire, said conductors being adapted for connection with standard plug terminal elements used in connecting electrical circuits. j

2. A device for protecting the tubes of a radio receiving set, comprising a casing of insulating material, electrical conductors in said casing comprising two sets of sectional conductors, one set being connected by a wire resistance and the other by a fuse wire, both resistance wire and fuse wire having a greater resistance than that ofthe tubes of the set to be protected, said conductors being adapted for connection with standard plu termi,- nal elements used in connecting e ectrical circuits of the character described.

3. A device for protecting the tubes of a radio receiving set, comprising a casin of insulating material made of twodupllcate half portions with grooves formed therein, two sets of electrical conductors located in said grooves two of each of which are duplicates and are located on opposite sides of the median line of the casing, a resistance wire connecting the adjacent ends of the conducwire and a. fuse wire connecting said conductors in freely separable relation, and means for connecting said casing portions together and clamping said conductors therein.

5. A device for protecting the tubes of a radio receiving set, comprising a casing of insulating material made in two half duplicate portions with grooves formed therein, electrical conductors in said casing located in said grooves and spaced apart longitudinally a resistance connecting the adjacent ends 0 said conductors, said casing having a chamber formed therein in which said resistance rests, means for holding the two casing ortions to ether and for clamping the con uctors in t e grooves.

6. A device for protecting the tubes of a radio receiving set com risingla ca of insulating materiaf ma e in two du licate half portions with grooves formed t erein, sectional conductors located in said grooves, means for preventing the conductors from moving longitudinally in said grooves, a resistance element connecting the adjacent ends of said sectional conductors located in one of said grooves, /and means for holdin said casing ortions together the elements t erein being eld by one portion of the casin in freely separable relation thereto when e casing portions are se arated.

7 A device or the purpose set forth comprising a casing of insulating material, sectional conductors therein spaced from each other longitudinally, a resistance wire of greater resistance than that of the tubes to be protected connecting the adjacent ends of saidconductors on one side of the median line and a conductor for connecting the adjacent ends of the sectional conductors'on the opposite side of the median line, two of said conductors extending beyond the end of the casing at one end thereof, and two bein housed within the casing at the opposite en thereof substantially as shown.

8. `A device for protecting the tubes of a radio receiving set, comprising a casing of insulating material made in two half portions which are duplicates, having grooves formed therein, sectional conductors arranged in pairs located in said grooves and freely removable therefrom when the casing portions are separated, said casing having a separate closed chamber, a resistance wire in said signature.

SIDNEY WEISBERG. 

